Oliver Hirschbiegel’s biopic of Diana could easily have seemed cynical and opportunistic in the extreme. Hirschbiegel is a distinguished German director who made a very well received film about Adolf Hitler in his bunker (Downfall), but it’s hard to see how that qualifies him to tell the story of the “people’s princess”.

Oliver Hirschbiegel’s biopic of Diana could easily have seemed cynical and opportunistic in the extreme. Hirschbiegel is a distinguished German director who made a very well received film about Adolf Hitler in his bunker (Downfall), but it’s hard to see how that qualifies him to tell the story of the “people’s princess”.

At tonight’s premiere, Hirschbiegel asked the audience to approach his film without preconceptions. That, of course, is impossible to do. However, Diana works well enough as a dark romantic drama and is far less exploitative than it might have been. Naomi Watts gives an intense and volatile performance as the princess. The problem, though, is that she doesn’t really resemble the character she is playing, and the feature shifts wildly in tone.

The film is set toward the end of Diana’s life and chronicles her secret love affair with Pakistani surgeon Hasnat Khan (Naveen Andrews). The brooding opening sequence set in the Ritz in Paris in 1997 on the night of her death is brilliantly shot. We see Diana from behind as she walks through her suite and toward the lift. Then, just as she is about to head out into the night with Dodi Fayed, we are whisked back two years.

At times, there is a novelettish quality to the storytelling in keeping with the tone of the Kate Snell book on which the film is based. When Diana first spots Hasnat in a London hospital, she is instantly smitten. He is a heart surgeon, she is the “queen of hearts”. She smuggles him into Kensington Palace and they eat hamburgers and watch football together. Andrews is personable and charming as the doctor, who smokes, drinks, loves jazz, but is also utterly devoted to saving lives. Diana dons a dark wig so she can accompany him incognito to Ronnie Scott’s, reads Grey’s Anatomy so she can talk to him about medicine and shows her devotion to him at one stage by washing up at his flat. At one stage, after an argument, she even puts on a Liverpudlian accent and pretends she is called Rita so he will take her call.

At this point, we seem to be veering in the direction of a Working Title romcom. However, there is a very dark strain to the storytelling. At times, as paparazzi crowd in and in the wake of her notorious Martin Bashir interview, she seems like a hunted animal. We learn about her self-harm. Watts’ performance carries echoes of her young ingénue, adrift in Hollywood and losing her sanity in David Lynch’s Mulholland Drive.

There are dutiful nods toward Diana’s work in the fight against Aids and as part of the campaign to ban landmines. We see her in Angola and in Pakistan, where she charms Hasnat’s family.

The historical accuracy of Diana is bound to be questioned. What makes it frustrating as a film, though, are its many sudden shifts in mood. Perhaps, Hirschbiegel could have made a stronger film if he hadn’t been lumbered with the baggage that the real Diana brings and had simply told a fictional story about a love affair between a princess and an outsider. That, though, would have defeated the purpose.